I used to think I understood MVC. In undergraduate CS programs, MVC is taught as an off-the-shelf pattern, explained once and then ready for use in the real world. Wikipedia also makes it seem pretty simple:

Model–View–Controller (MVC) is an architectural pattern used in software engineering. Successful use of the pattern isolates business logic from user interface considerations, resulting in an application where it is easier to modify either the visual appearance of the application or the underlying business rules without affecting the other. In MVC, the model represents the information (the data) of the application; the view corresponds to elements of the user interface such as text, checkbox items, and so forth; and the controller manages the communication of data and the business rules used to manipulate the data to and from the model.

They go on to show the classic triangle diagram and how it’s baked into various GUI and web frameworks. There’s only one clause in the entire article that hints at something deeper: “Though MVC comes in different flavors…”

Different flavors indeed. In fact MVC is not just a pattern but a whole family of patterns: MVC, MVA, MVP, PAC, Model-Delegate…. It very quickly gets very hairy.

In this article I want to describe one of MVC’s lesser-known variants, the Model-View-Adapter (MVA) pattern, and talk about its advantages over traditional MVC in the context of a Java Swing application.

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